Frequency measurements of the gyrotrons used for collective Thomson scattering diagnostics at TEXTOR and ASDEX Upgrade

Journal Article · Sun Oct 15 04:00:00 EDT 2006 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.2347694· OSTI ID:20861231

Woskov, P; Bindslev, H; Leipold, F; Meo, F; Nielsen, S K; Tsakadze, E L; Korsholm, S B; Scholten, J; Tito, C; Westerhof, E; Oosterbeek, J W; Leuterer, F; Monaco, F; Muenich, M; Wagner, D ^[1]

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1. MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States)

High resolution frequency measurements of the 110 GHz gyrotron at TEXTOR and the 105 GHz mode of the two-frequency gyrotron (Odissey-1) at ASDEX Upgrade (AUG) have been made in support of fast ion collective Thomson scattering diagnostics. Measurements were done by harmonic heterodyne methods using both fast Fourier transform spectroscopy with digital oscilloscopes and fast scanning spectrum analyzers. Accurate frequencies were obtained with a frequency counter. At TEXTOR, at 180 kW forward power the starting frequency was 109.970{+-}0.005 GHz and chirped down as much as 27 MHz depending on the duty factor. At AUG, at 500 kW forward power the frequency started at 104.786 GHz and chirped down 104 MHz, with 90% of the chirp occurring in the first 100 ms. Plasma perturbation of the TEXTOR gyrotron was observed when both ion cyclotron resonance heating antennas and neutral beam injection were operating, producing modulation at 29 and 58 MHz in the gyrotron output. Each gyrotron was observed to have an instrumental measurement limited linewidth of 120 kHz full width at half maximum.

• OSTI ID: 20861231
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 10 Vol. 77; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANTENNAS
ASDEX TOKAMAK
CONFINEMENT
FOURIER TRANSFORMATION
FREQUENCY MEASUREMENT
FREQUENCY MODULATION
GHZ RANGE 100-1000
ICR HEATING
KHZ RANGE 100-1000
MHZ RANGE
MICROWAVE AMPLIFIERS
PLASMA
PLASMA BEAM INJECTION
PLASMA DIAGNOSTICS
SPECTROSCOPY
TEXTOR TOKAMAK
THOMSON SCATTERING